Add initial CI

.github/workflows/crystal.yml

@@ -0,0 +1,32 @@
+name: Crystal CI
+
+on:
+  - push
+  - pull_request
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    container:
+      image: crystallang/crystal
+
+    services:
+      redis:
+        image: redis/redis-stack-server
+        # Set health checks to wait until redis has started
+        options: >-
+          --health-cmd "redis-cli ping"
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Install dependencies
+      run: shards install
+    - name: Run tests
+      run: crystal spec
+      env:
+        REDIS_URL: redis://redis/

src/connection.cr

@@ -21,7 +21,7 @@ module Redis
     # SSL connections require specifying the `rediss://` scheme.
     # Password authentication uses the URI password.
     # DB selection uses the URI path.
-    def initialize(@uri = URI.parse("redis:///"))
+    def initialize(@uri = URI.parse(ENV.fetch("REDIS_URL", "redis:///")))
       host = uri.host.presence || "localhost"
       port = uri.port || 6379
       socket = TCPSocket.new(host, port)